Hydraulic diaphragm brake



Jan. 13, 1942.

R. DE FILIPPIS y HYDRAULIC DIAPHRAGM BRAKE Filed sept.. 27, A1959ATTORNEY.

Patented Jan. 13, 1942 r UNITED STATES PATENT OFFICE HYDRAULIC DIAIHRAGMBRAKE Raymond de Filipps, Brooklyn, N, Y.

Application September 27, 1939, Serial No. 296,721

(Cl. 18S-99) 6 Claims.

- Thsinvention relates to hydraulic brakes.

One object of the invention is to provide such an improved brake whichshall not require the use of .pumps for creating the retardation factor.

Heretofore hydraulic-brakes have always employed pumps, generally of thereciprocatory type, so that when a suitable valve was closed, movementof the pump'piston and hence of a transmission or a shaft was retardedor prevented. These pumps were an element of considerable expense inregard to manufacture, up-l keep and consumption of power, and so impor-Another object of the invention is the provision of an improved brakehaving a fluid responsive vibratable element which is inherently fluid-ftight and which is hydraulically controllable to cause a braking actionto be exerted for stopping the rotation of a member.

Another object of the invention is to provide an improved brake systemcomprising a plurality of-"elements each hydraulically operable insuctionand in compression under control of a valve member and theelements being so related that one ofthem acts in compression while theother acts in suction to thus continuously kafford a pressure reactionfor braking.

Another Object of the invention is to provide an improved brake sosimple and inexpensive as to permit a separate one to be provided foreach ofv the four wheels of an automobile, with preferably a singlevalve control for all of them, so constructed and arranged ythat if oneof the brakes developed a leak, operation of the other brakes would notbe affected.

-Another object of the invention is the provision of a brake havingimproved means including an expandible, collapsible hydrauliccompartment responsive to the rotation of a member and adapted tosuccessively produce pressure suction conditions in the compartment forbraking the member, and with the pressure condition ultimately availableto cause the maximum braking action, if required.

VYA further object of the invention is to provide a device of thecharacter described having relatively iew and simple parts, and which isinexpensive to assemble, compact, durable, reliable andieftlcient inuse.

Other objects and advantages of the invention will become yapparent asthe specication proceeds. *Y

With-the aforesaid objects in view, the invention consists in the novelcombination and arrangements of parts hereinafter described in theirpreferred embodiments, pointed out in the subjoined claims, andillustrated in the annexed drawing, wherein like parts are designated bythe same reference characters throughout the several views.

- In the drawing:

Figure 1 is a diagrammatic View, with parts in section, and certainparts removed, showing a device embodying the invention.

Fig. 2-is a fragmentary end view of a part of the device, including thevalve means.

Fig. Bis a schematic view with parts in elevation showing a modifiedform of the invention appliedto one of the wheels of a car.

- The advantages of the invention as here 'outlined are best realizedwhen all of its features and instrumentalities are combined in one andthe same structure, but, useful devices may be producedembodying lessthan the whole.

VItlwill be-obvious to those skilled in the art to which 4the inventionappertains, that the same may be incorporated in several differentconstructions. .The accompanying drawing, therefore, v is submittedmerely as showing the preferred exemplification of the invention.

1 Referring in detail to the drawing, I0 denotes a device, such as apower transmission or brake system,v v embodying the invention. The samemayinclude avrotary means, as, for instance, one ormore .wheels II andI2, the former representing-ione of the front steering wheels and thelatter 'representing one of the rear drive wheels of an automobile'.These wheels are mounted in any.' conventional or suitable manner. Tosmplify the drawing, these wheels are shown asv mounted on their.respective trunnions or shafts I3, I4. l Any 'desired means forconverting rotary into .-reciprocatory motion may include eccentricmembers I5 connected to said Wheels or to the elements I3,.I4. Mountedon the members I5 are wthe eccentricstraps I6 having their connecting.rod portions I1 engaged with my novel brake means to cause expansiblecollapsible movement ofa hydraulic compartment by llexure of a wallofthe latter, as will now be described.

The brake means I8 may include any well known type ofexpandible-collapsible compartment'having aflexible wall, and beingoperative in 4response to internal hydraulic pressure. It is-understoodthat the device may have wide or narrow limits of expandibility and ofcollapsibility. The preferred embodiment of the invention includes acasing having casing sections I9, concaved toward each other and betweenwhich is powerfully marginally clamped a disc shaped diaphragm 2ladapted to be supported by said sections in the extreme positions of thediaphragm. The latter may be made of a corded, fluidtight fabric; it mayconsist of rubber or other suitable flexible material reenforced, ifnecessary, with a textile fabric or the like which may be impregnatedand coated with a fluid tight composition. Unlike a metallic diaphragm,such a diaphragm possesses almost indefinite life, if only it be mountedto avoid thev wearing or cutting action of corners or points.` And itmay have suflicient strength to withstand the highest stresses to whichit may be subjected 'in normal use in an automobile four wheel brakesystem.

Outwardly dished metallic plates 22 on opposite sides of the diaphragmare interconnected by a central pin 23 to form a strong anchoragecarrying a knuckle 24 to which the eccentric rod I'I is pivotallyconnected as at 25. The casing member 2l) may have a concentric opening26 for the knuckle 24. To maintain accurate spacing between the casingsI9, 20 and the Wheel centers, and to pl-ace the strain at a desirablepoint, supporting members or bars 2'I arev connected at one end to thecasing members 20 and at their other ends to the membersv I3vand I4respectively or to a bearing housing of the latter as schematicallyindicated at 21a, Of course, additional support for the casings I9, 20may be provided from the frame of the automobile, or from an auxiliaryframe carrying the wheel shafts, but such additional supports need notbe shown.

Controlling the diaphragm 2l hydraulically is a valve means 28` which ispreferably arranged as a common control for the diaphragms at each ofthe four wheels of the automobile. Mounting the valve means isa casing!l which may comprise a liquid reservoir section 3l),v closed by a plateSI carrying a vent or breatherelement 32. At its bottom, the rcasing 29may have a casing section 33 for the valve 28. The latter mayillustratively consist of a cylindrical bar journaled at its ends inrecessed or bearing portions of the casing as at 351, and having oneorimore transverse openings or passages 3.5 therethrough forindividually controlling the passages 36yto the desirably flexibleconduits 31, 33; Of these the conduits 3'! may lead to the. front wheeldiaphragms and the conduits 38 may lead Vto the rear wheel diaphragms.Thus hydraulic compartments 39 are provided, having flexible walls 2land being collapsible and expansible by the eccentrics It and beingcontrollable by the valve 28.

The valve 28 may be manually operated as by an axial valve stern 4I)having an arm IIIl connected by a link 42 to a foot pedal 43. A ten-.-sion coil spring M tends to move the arm 4I against a stop 45 to limitthe opening movement of the valve. closing movement of the valve underthe pressure of the brake pedal.

The operation of the device I will now be briey described. It will beperceived that when the valve 28 is open, the diaphragms merelyoscillate to and fro in response to the movement of the automobile, withthe gas or liquid in the system moving in part into` and out of thereservoir 3l! as the compartments 39 expand. and.

A similar stop 46 may limit thecollapse. To set the brake in action, thevalve 28 is wholly or partially closed, slowly or rapidly as required.Assume that the valve is wholly closed. The diaphragm 2| may be under a.stress toward the right or toward the left depending on the position ofthe eccentric at the given instant. If the stress is toward the left,the hydraulic fluid is under pressure which resists movement of thediaphragm and hence of thel eccentric thus retarding or stopping themotion of the wheel. If the stress is toward the right, the hydraulicfluid is subject to greatly reduced pressure or suction which similarlyresists movement of the diaphragm to exert the braking action. The useof a liquid is naturally the best as absolute zero pressure is morereadily attained on suction. In Fig, 1 the diaphragm is shown at theright so that the pressure condition obtains, in Fig. 2, the diaphragmis shown centrally to illustrate a different position in which eitherpressure or suction may occural though in this instance the conditionwill be one ofpressure. Since the automobile wheels may not maintain asynchronous condition it' is desirable that the device I Gbe operativeunder both pressure and suction conditions. This is readily attained bymaking the compartments 39. wholly closed except for. the opening actionof the valve 28.

The advantages of the present invention in simplicity, cheapness andreliability will be readily apparent. Moreover, if a leak should developat one of the diaphragms, the others may continue to satisfactorilyoperata, especially in view of the oil reservoir 30. The latter tends tokeepl the compartments@ always full. In fact individual reservoirs areprovided for the different compartments, as by providing passages 41alined with the respectivevpassagesv 36, and each passage i'I havingsufficient capacity to fill the'- compartment 35iA at its maximumvolume.

In 3 is shown a modification of the invention according to a principlesuch as to affordr continuous pressure reactionY toI exert the brakf ingforce of a vehicle. Since the maximum diaphragm stress per unit area islimited in suction, it is desirable that pressure be continuouslyavailable in order to permit the use of a substantally higher stress perunit area on` the dia.- phragm, thus permitting the size of theAdiaphragms to be reduced and to permit of greater braking force to beavailable. In this gure, the device is shown applied'to one wheel,A butit will be understood that it may be similarly applied toall of thewheels of an automobile-in thefsame general manner as shown in Fig. 1,except: that an additional diaphragmgmay be provided forv each wheel.

Thus I provide an additional diaphragmY 2Ia within a casing I9a,2ila-with the-provision of an internal expansibl'eecollapsiblecompartment at the right of said diaphragm, said compartment beingconnected by conduit 31a with thevalve structure 33; It will beunderstood that separate.A passages 35 anddl areprovided for theconduit3M, in consequence of which there will be twice as many such passages inthe valve structure of Fig. 2, if two diaphragms are provided for eachof the four wheelsof an automobile. Connected to the diaphragm 2Ia is anarm Ila which may be a rigid part of the eccentric Iathat corresponds tothe eccentric I6. It will be understood that as thus far described allof the construction associated `with thediaphragm 2Ia is identical. tothat providedfor the diaphragm 2|, and that the expansible-collapsiblecompartments may in both instances be of like capacity. The essentialdifference is in the mode of operation, since with the wheel turning inthe direction of the arrow a, the arms I1 and Ila will move in thedirection of the arrow b. Consequently there will be a pressureresistance to the diaphragm 2| and suction resistance to the diaphragm2Ia. When the arms I1, Ila are moving in the opposite direction, thediaphragm 2Ia will then be subject to pressure resistances, while thediaphragm 2| will be subject to suction resistance. By thus alternatingthe character of the stress, it will be noted that pressure resistanceis available substantially all the ltime and regardless of the positionof the wheel at the instant that the braking force is applied. By theuse of a single eccentric structure for both diaphragms, the cost of thedevicek is reduced, but the arrangement shown is intended to beillustrative. 'I'he two like eccentrics Ita with their respective rodsl1, Ila Will have the common eccentric cam I5. A part of one of theeccentrics I6a has been removed in Fig. 3.

I claim:

1. An automobile including a plurality of shafts each adopted to mountone or more Wheels, a unit for each Wheel having a compartment memberhaving a diaphragm, means interengaging the diaphragms with the diierentwheels, each means including an eccentric element to cause of saidmeans, said compartments hydraulically` restraining the movement oftheir respective diaphragms when the valve member is in closed position.

2. A device including a plurality of brake units, each unit including amember having a flexible Wall and providing a compartment which isexpandible-collapsible by movement of said Wall, means connecting saidmember with a rotary means to cause movement of the flexible Walls, anda single valve unit for opening and closing the compartments of thedifferent units to interpose different hydraulic resistances to themovement of said flexible walls, said valve unit having differentcompartments, and individual reservoirs for the valve openings at a sidethereof remote from said compartments.

3. A device including a plurality of brake units, each unit including amember having an elementA movable in opposition to hydraulic pressuredermovement of said element, means connectingI said member with a rotarymeans to cause movement of the element, and a single valve unit foropening and closing the compartments of the different units to interposedifferent hydraulic resistances to the movement of said elements, saidvalve unit having different compartments, and individual reservoirs forthe valve openings at a side thereof remote from said compartments.

4. A hydraulic brake system for automobiles, a casing, a flexiblediaphragm dividing the casing into a first section and a secondsection,l the diaphragm being substantially fully movable into eithercasing section and being adapted for supporting engagement with thelatter, a liquid reservoir, a conduit connecting the reservoir with thefirst section, a valve in said conduit, said conduit and said firstsection being liquid-filled, said valve ycooperating with the rstsection to restrict the movement of the diaphragm When the valve isclosed and to permit free movement ofthe diaphragm when the valve isopen, the second section having an opening, and means including aneccentric connecting the diaphragm with a Wheel of the automobile sothat rotation of the Wheel causes said movement of the diaphragm, saidmeans comprising a connecting element extending freely through saidopening.

5.k A hydraulic brake system for an automobile including a casing, aexible diaphragm mounted in the casing and dividing the same into a rstcasing section and into a second casing section, a valve controlledconduit connected to the i'lrst section for controlling the diaphragm,the conduit and the first section being liquid lled, means including aneccentric for connecting the diaphragm with a Wheel of the automobile,and the rst and second sections constituting compartments into which thediaphragm can be deected, with said sections having outer Walls of suchsize and curvature as toi-lt the diaphragm in its deected position.

6. A hydraulic brake including a casing, a flexible diaphragm mountedtherein, a rotary shaft operatively connected to the diaphragm tovibrate the same, hydraulic means communicating with one side of thediaphragm, a valve for said hydraulic means to cause the same to opposedifferent required resistances to the diaphragm for a variable brakingaction on the shaft under the sole control of said valve, and manualmeans for normally operating the valve,` said shaft being angularlymovable, means mounting said casing for angular movement with saidshaft, said valve being relatively stationary, and the hydraulic meanscomprising a ilexiblel conduit'connected to the casing.

` RAYMOND DE FILIPPIS.

